A Convergent Approach to the Dihydrotachysterol Diene System. Application to the Synthesis of Dihydrotachysterol2 (DHT2), 25-Hydroxydihydrotachysterol2 (25-OH-DHT2), 10(R),19-dihydro-(5E)-3-epivitamin D2, and 25-Hydroxy-10(R),19-dihydro-(5E)-3-epivitamin D2

Article abstract of DOI:10.1021/jo00045a038

Total synthesis of A-ring fragments of 10(S),19-dihydrovitamins D and 10(R),19-dihydro-(5E)-epivitamins D from (+)-(S)-carvone and (-)-(R)-carvone is described.These fragments were used for convergent synthesis of dihydrotachysterol₂ (DHT₂), 25-hydroxydihydrotachysterol₂, 10(R),19-dihydro-(5E)-3-epivitamin D₂, and 25-hydroxy-10(R),19-dihydro-(5E)-3-epivitamin D₂.